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HarmonyOS
目前应用有个场景，需要对用户身份做认证，需要用户上传身份证正面和国徽面，希望在拍照片的时候在拍摄页面上加一个身份证半透明提示(或者国徽半透明照片)，以提醒用户当前需要拍摄身份证正面(或者国徽面)请问这该怎么操作?
解决方案
参考demo：
import abilityAccessCtrl, { Context, PermissionRequestResult, Permissions } from '@ohos.abilityAccessCtrl';
import { BusinessError } from '@ohos.base';
import common from '@ohos.app.ability.common';
import camera from '@ohos.multimedia.camera';
import { image } from '@kit.ImageKit';
import { photoAccessHelper } from '@kit.MediaLibraryKit';
import fs from '@ohos.file.fs';
let context = getContext(this);
@Entry
@Component
struct PagePreview {
mXComponentController: XComponentController = new XComponentController;
surfaceId: string = '';
isUserAgent: boolean = false
@State pixelMap: PixelMap | undefined = undefined
@State photoOutput: camera.PhotoOutput | undefined = undefined;
getPermission(permissions: Permissions[]): Promise<boolean> {
let atManager: abilityAccessCtrl.AtManager = abilityAccessCtrl.createAtManager();
let context: Context = getContext(this) as common.UIAbilityContext;
return new Promise((resolve, reject) => {
atManager.requestPermissionsFromUser(context, permissions,
(err: BusinessError, data: PermissionRequestResult) => {
if (err) {
console.log(`requestPermissionsFromUser fail, err->${JSON.stringify(err)}`);
return resolve(false)
} else {
console.info('data:' + JSON.stringify(data));
console.info('data permissions:' + data.permissions);
console.info('data authResults:' + data.authResults);
return resolve(true)
}
});
})
}
async savePicture(buffer: ArrayBuffer, img: image.Image): Promise<void> {
let imageResource = image.createImageSource(buffer);
imageResource.createPixelMap({}).then((res) => {
this.pixelMap = res;
});
return
let accessHelper: photoAccessHelper.PhotoAccessHelper = photoAccessHelper.getPhotoAccessHelper(context);
let options: photoAccessHelper.CreateOptions = {
title: Date.now().toString()
};
let photoUri: string = await accessHelper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'jpg', options);
//createAsset的调用需要ohos.permission.READ_IMAGEVIDEO和ohos.permission.WRITE_IMAGEVIDEO的权限
let file: fs.File = fs.openSync(photoUri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
await fs.write(file.fd, buffer);
fs.closeSync(file);
img.release();
}
setPhotoOutputCb(photoOutput: camera.PhotoOutput): void {
//设置回调之后，调用photoOutput的capture方法，就会将拍照的buffer回传到回调中
photoOutput.on('photoAvailable', (errCode: BusinessError, photo: camera.Photo): void => {
console.info('getPhoto start');
console.info(`err: ${JSON.stringify(errCode)}`);
if (errCode || photo === undefined) {
console.error('getPhoto failed');
return;
}
let imageObj = photo.main;
imageObj.getComponent(image.ComponentType.JPEG, (errCode: BusinessError, component: image.Component): void => {
console.info('getComponent start');
if (errCode || component === undefined) {
console.error('getComponent failed');
return;
}
let buffer: ArrayBuffer;
if (component.byteBuffer) {
buffer = component.byteBuffer;
} else {
console.error('byteBuffer is null');
return;
}
this.savePicture(buffer, imageObj);
});
});
}
async cameraShootingCase(baseContext: common.BaseContext, surfaceId: string): Promise<void> {
// 创建CameraManager对象
let cameraManager: camera.CameraManager = camera.getCameraManager(baseContext);
if (!cameraManager) {
console.error("camera.getCameraManager error");
return;
}
// 监听相机状态变化
cameraManager.on('cameraStatus', (err: BusinessError, cameraStatusInfo: camera.CameraStatusInfo) => {
console.info(`camera : ${cameraStatusInfo.camera.cameraId}`);
console.info(`status: ${cameraStatusInfo.status}`);
});
// 获取相机列表
let cameraArray: Array<camera.CameraDevice> = cameraManager.getSupportedCameras();
if (cameraArray.length <= 0) {
console.error("cameraManager.getSupportedCameras error");
return;
}
for (let index = 0; index < cameraArray.length; index++) {
console.info('cameraId : ' + cameraArray[index].cameraId); // 获取相机ID
console.info('cameraPosition : ' + cameraArray[index].cameraPosition); // 获取相机位置
console.info('cameraType : ' + cameraArray[index].cameraType); // 获取相机类型
console.info('connectionType : ' + cameraArray[index].connectionType); // 获取相机连接类型
}
// 创建相机输入流
let cameraInput: camera.CameraInput | undefined = undefined;
try {
cameraInput = cameraManager.createCameraInput(cameraArray[0]);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to createCameraInput errorCode = ' + err.code);
}
if (cameraInput === undefined) {
return;
}
// 监听cameraInput错误信息
let cameraDevice: camera.CameraDevice = cameraArray[0];
cameraInput.on('error', cameraDevice, (error: BusinessError) => {
console.error(`Camera input error code: ${error.code}`);
})
// 打开相机
await cameraInput.open();
// 获取支持的模式类型
let sceneModes: Array<camera.SceneMode> = cameraManager.getSupportedSceneModes(cameraArray[0]);
let isSupportPhotoMode: boolean = sceneModes.indexOf(camera.SceneMode.NORMAL_PHOTO) >= 0;
if (!isSupportPhotoMode) {
console.error('photo mode not support');
return;
}
// 获取相机设备支持的输出流能力
let cameraOutputCap: camera.CameraOutputCapability =
cameraManager.getSupportedOutputCapability(cameraArray[0], camera.SceneMode.NORMAL_PHOTO);
if (!cameraOutputCap) {
console.error("cameraManager.getSupportedOutputCapability error");
return;
}
console.info("outputCapability: " + JSON.stringify(cameraOutputCap));
let previewProfilesArray: Array<camera.Profile> = cameraOutputCap.previewProfiles;
if (!previewProfilesArray) {
console.error("createOutput previewProfilesArray == null || undefined");
}
let photoProfilesArray: Array<camera.Profile> = cameraOutputCap.photoProfiles;
if (!photoProfilesArray) {
console.error("createOutput photoProfilesArray == null || undefined");
}
// 创建预览输出流,其中参数 surfaceId 参考上文 XComponent 组件，预览流为XComponent组件提供的surface
let previewOutput: camera.PreviewOutput | undefined = undefined;
try {
previewOutput = cameraManager.createPreviewOutput(previewProfilesArray[0], surfaceId);
} catch (error) {
let err = error as BusinessError;
console.error(`Failed to create the PreviewOutput instance. error code: ${err.code}`);
}
if (previewOutput === undefined) {
return;
}
// 监听预览输出错误信息
previewOutput.on('error', (error: BusinessError) => {
console.error(`Preview output error code: ${error.code}`);
});
// 创建拍照输出流
let photoOutput: camera.PhotoOutput | undefined = undefined;
try {
photoOutput = cameraManager.createPhotoOutput(photoProfilesArray[0]);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to createPhotoOutput errorCode = ' + err.code);
}
if (photoOutput === undefined) {
return;
}
//调用上面的回调函数来保存图片
this.setPhotoOutputCb(photoOutput);
//创建会话
let photoSession: camera.PhotoSession | undefined = undefined;
try {
photoSession = cameraManager.createSession(camera.SceneMode.NORMAL_PHOTO) as camera.PhotoSession;
} catch (error) {
let err = error as BusinessError;
console.error('Failed to create the session instance. errorCode = ' + err.code);
}
if (photoSession === undefined) {
return;
}
// 监听session错误信息
photoSession.on('error', (error: BusinessError) => {
console.error(`Capture session error code: ${error.code}`);
});
// 开始配置会话
try {
photoSession.beginConfig();
} catch (error) {
let err = error as BusinessError;
console.error('Failed to beginConfig. errorCode = ' + err.code);
}
// 向会话中添加相机输入流
try {
photoSession.addInput(cameraInput);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to addInput. errorCode = ' + err.code);
}
// 向会话中添加预览输出流
try {
photoSession.addOutput(previewOutput);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to addOutput(previewOutput). errorCode = ' + err.code);
}
// 向会话中添加拍照输出流
try {
photoSession.addOutput(photoOutput);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to addOutput(photoOutput). errorCode = ' + err.code);
}
// 提交会话配置
await photoSession.commitConfig();
// 启动会话
await photoSession.start().then(() => {
console.info('Promise returned to indicate the session start success.');
});
// 判断设备是否支持闪光灯
let flashStatus: boolean = false;
try {
flashStatus = photoSession.hasFlash();
} catch (error) {
let err = error as BusinessError;
console.error('Failed to hasFlash. errorCode = ' + err.code);
}
console.info('Returned with the flash light support status:' + flashStatus);
if (flashStatus) {
// 判断是否支持自动闪光灯模式
let flashModeStatus: boolean = false;
try {
let status: boolean = photoSession.isFlashModeSupported(camera.FlashMode.FLASH_MODE_AUTO);
flashModeStatus = status;
} catch (error) {
let err = error as BusinessError;
console.error('Failed to check whether the flash mode is supported. errorCode = ' + err.code);
}
if (flashModeStatus) {
// 设置自动闪光灯模式
try {
photoSession.setFlashMode(camera.FlashMode.FLASH_MODE_AUTO);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to set the flash mode. errorCode = ' + err.code);
}
}
}
// 判断是否支持连续自动变焦模式
let focusModeStatus: boolean = false;
try {
let status: boolean = photoSession.isFocusModeSupported(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO);
focusModeStatus = status;
} catch (error) {
let err = error as BusinessError;
console.error('Failed to check whether the focus mode is supported. errorCode = ' + err.code);
}
if (focusModeStatus) {
// 设置连续自动变焦模式
try {
photoSession.setFocusMode(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to set the focus mode. errorCode = ' + err.code);
}
}
// 获取相机支持的可变焦距比范围
let zoomRatioRange: Array<number> = [];
try {
zoomRatioRange = photoSession.getZoomRatioRange();
} catch (error) {
let err = error as BusinessError;
console.error('Failed to get the zoom ratio range. errorCode = ' + err.code);
}
if (zoomRatioRange.length <= 0) {
return;
}
// 设置可变焦距比
try {
photoSession.setZoomRatio(zoomRatioRange[0]);
} catch (error) {
let err = error as BusinessError;
console.error('Failed to set the zoom ratio value. errorCode = ' + err.code);
}
let photoCaptureSetting: camera.PhotoCaptureSetting = {
quality: camera.QualityLevel.QUALITY_LEVEL_HIGH, // 设置图片质量高
rotation: camera.ImageRotation.ROTATION_0 // 设置图片旋转角度0
}
// 使用当前拍照设置进行拍照
photoOutput.capture(photoCaptureSetting, (err: BusinessError) => {
if (err) {
console.error(`Failed to capture the photo ${err.message}`);
return;
}
console.info('Callback invoked to indicate the photo capture request success.');
});
}
aboutToAppear(): void {
//user_grant用户授权
this.getPermission(['ohos.permission.CAMERA']).then(async (res) => {
console.log(String(res))
if (!res) {
return
}
})
}
aboutToDisappear(): void {
}
build() {
Column() {
// 创建XComponent
Stack(){
XComponent({
id: '',
type: 'surface',
libraryname: '',
controller: this.mXComponentController
})
.onLoad(() => {
// 设置Surface宽高（1920*1080），预览尺寸设置参考前面 previewProfilesArray 获取的当前设备所支持的预览分辨率大小去设置
// 预览流与录像输出流的分辨率的宽高比要保持一致
this.mXComponentController.setXComponentSurfaceSize({ surfaceWidth: 640, surfaceHeight: 980 });
// 获取Surface ID
this.surfaceId = this.mXComponentController.getXComponentSurfaceId();
})
.width('100%')
.height('100%')
.zIndex(1)
Row(){}.width('100%')
.height('100%').zIndex(2).backgroundColor(Color.Black).opacity(0.6)
Button("拍照").onClick(async () => {
await this.cameraShootingCase(getContext(), this.surfaceId)
}).zIndex(3)
}
}
.height('100%')
.width('100%')
}
}撰写回答
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参考demo：